Convert 20121004 (yyyyMMdd) to a valid date time?

Question

I have a string in the following format yyyyMMdd and I am trying to get it to look like this:

yyyy-MM-dd

When I try:

Answer 1

I get the error:

FormatException: String was not recognized as a valid DateTime.

You are getting this error because you are not telling the ToDateTime() method how to figure out to parse your string.

If you use the following method:

public static DateTime ParseExact(
    string s,
    string format,
    IFormatProvider provider,
    DateTimeStyles style
)

You won't get this error. After you generate a DateTime variable just display it in the format yyyy-dd-mm using the ToString() method.

public string ToString(
    string format,
    IFormatProvider provider
)

http://msdn.microsoft.com/en-us/library/8tfzyc64
http://msdn.microsoft.com/en-us/library/9h21f14e

I know this basically repeats the same information as everyone else but it also provides him the ability to understand what the two methods he needs to use actually does.